The battle of the demigods

"It may be hard to believe, but Greek gods do exist. They sometimes have affairs with mortals, which results in children who are half mortal, half divine, the demi-gods...
- Like you?' asked Michael.
- No, Michael... like us. You're also a demigod. One of your parents was born 1300 years before Christ. You're an important child, one of THEIR children.
- Am I... I'm a demigod? But who are you? Who is my divine parent?
- I am Lyzarra Louvelin and my mother is Artemis. I'll explain everything to you on the way. We have to join the others at the camp before nightfall...
- Wait... what?! Michael's eyes widened. Are there other demigods waiting for us?
- Yes,' replied Lyzarra. Come on, Michael, we've got a long way to go before we get to the camp..."

Michael is an ordinary teenager living peacefully in an orphanage, where he leads a simple, gloomy life... until the day when a monster from the bowels of the earth arrives, straight out of Greek mythology, with a single thought in mind: to eliminate Michael. Saved in extremis by a heroine who turns out to be the daughter of a goddess, Lyzarra reveals to Michael the true nature of his origins. One of his parents is a mere mortal, but the other is a god of immeasurable power. Disorientated, Michael is taken to a camp where there are other people like him: demigods. It soon becomes clear why he is in the camp: there is a threat hanging over the Earth and even the gods can't face it alone, at least not without the help of their children. Michael, Lyzarra and twelve other teenagers, sons and daughters of the gods of Olympus, embark on a quest fraught with danger to prevent the total annihilation of all life on Earth.